The present invention relates to improved solutions for conveying and processing dynamo-electric machine components (e.g., armatures or stators for electric motors, generators, or alternators) through resin application process steps.
Resin application steps are common in the manufacturing of dynamo-electric machine components. The dynamo-electric machine components such as armatures include insulated wire coils wound on ferromagnetic cores. Electric current passes through the wire coils in the operation of the dynamo-electric machine in which the component is used. For optimal performance of the dynamo, the dynamo-electric machine components' wire coils may be subject to tight dimensional tolerances. However, the wires in the coils, which are mechanically wound, are susceptible to loosening by vibration or heat during further manufacturing or assembly steps. Operation of the dynamo-electric machine itself may also cause vibrations and heat, which tend to loosen the wire coils. Electrical current, which passes through the wire coils, also may generate electro-mechanical forces that tend to loosen or deform the wire coil shape. To avoid distortion of the wire coil dimensions due to these or other causes, the wires in a coil are customarily coated and encased in an adhesive bonding material matrix such as a resin. The resin mechanically stabilizes the wire coil by binding the wires in the coil together, and thereby preventing relative movement of the wires. Additionally, the resin coating provides a heat conduction path to dissipate heat generated in the wires. The resin coating also protects the wire insulation from abrasion during further steps of the manufacturing process and during the operation of the dynamo-electric machine.
The resin coating and bonding process steps are carried out in the dynamo-electric manufacturing process using resin application stations. Resin application stations may, for example, include resin impregnation machines in which liquid dispensers trickle liquid resins on to the wire coils. The dispensed liquid resin impregnates the wire coils by filling up interwire spaces, for example, by capillary action. Alternatively, resin impregnation machines may dip the components in liquid baths to coat the wires with the resin. A resin application station usually involves additional machines for preparing the dynamo-electric machine components for resin impregnation, and for curing or hardening the impregnated liquid resin. These additional machines may include pre-heating units or curing units for regulating the temperature of the components during the resin application process. Resin application stations are integrated into manufacturing assembly lines by the use of suitable component holding devices and conveyor apparatus. The conveyor apparatus may carry components in pallets on belts running between the resin application stations and other processing stations in the assembly line.
Resin impregnation machines and ovens that are used in resin application stations, particular dispositions of resin application stations along an assembly line, transport routes by which the component-carrying pallets reach the stations, and sequences by which the pallets reach the stations have been described, for example, in Santandrea et al. U.S. Pat. No. 4,984,353, Cardini et al. U.S. Pat. No. 5,443,643, Cardini et al. U.S. Pat. No. 5,569,439, Faraoni et al. U.S. Pat. No. 5,401,531, Galassi et al. U.S. Pat. No. 5,919,308, Galassi et al. U.S. Pat. No. 6,024,795, and Becherucci et al. U.S. patent application Ser. No. 09/409,038, Becherucci et al. U.S. Pat. No. 6,226,857, and Sabatino et al. European Patent 0,757,425, all of which are hereby incorporated by reference herein in their entireties.
The uniformity and reproducibility dynamo-electric machine manufacturing processes are sensitive to variations in processing conditions. For example, in resin application processes, for example, resin viscosity and consequently resin settling may be affected by variations or fluctuations in temperature.
Consideration is now being given generally to ways of providing solutions for improving uniformity and reproducibility in dynamo-electric machine component manufacture. Attention is directed to resin application stations including resin impregnation machines, heating units, and curing units, with a view to improve the resin coating process and to improve the overall efficiency of dynamo-electric machine component manufacturing.